Health feed

ABSTRACT

The present invention relates to a method of promoting immunoglobulin A secretion in the mucosal membranes of non-human animals. The method comprises administering a foodstuff comprising glutamine to the non-human animal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage Application of InternationalApplication No. PCT/GB02/0752 filed Jun. 13, 2002, which claims priorityto Great Britain Application No. 0114419.5 filed Jun. 13, 2001, whichare incorporated herein in their entirety.

TECHNICAL FIELD

The present invention relates to a method of promoting immunoglobulin Asecretion in the mucosal membranes of non-human animals. The methodcomprises administering a foodstuff comprising glutamine to thenon-human animal.

BACKGROUND OF THE INVENTION

Glutamine is a neutral amino acid, which is readily transported acrossplasma membranes. As an important intermediate in a number of metabolicpathways, cellular utilization of glutamine can far exceed that of otheramino acids especially within intestinal and immune cells. Glutamine isimportant in the transport of amino nitrogen and ammonia, as a substratein gluconeogenesis and ammoniagenesis, as a fuel source for rapidlydividing cells and may also be involved in the regulation of proteinsynthesis.

The high rate of glutamine utilization by the intestine (identified tooccur in man) may be due in part to the large lymphocyte and macrophagepopulations in intestinal walls and Peyer's patches. These cells exhibithigh glutaminase activity and utilize glutamine as their preferentialfuel source, even in the quiescent state. However, as with many othercells that require glutamine, both enterocytes and lymphocytes lack thesynthetic apparatus to produce glutamine relying solely on circulatoryor dietary sources. It is suggested that a fall in the plasmaconcentration could compromise lymphocyte function accounting for theincrease in susceptibility to viral infection.

Gut-associated lymphoid tissue in the gastrointestinal tract appears toprovide immunologic protection for the gastrointestinal tract and forextra intestinal mucosal sites such as the nasopharynx, mammary glands,salivary glands and lungs. Lymphocytes, which provide or control theproduction of immunoglobulin A are released by the gut-associatedlymphoid tissue and distributed to the gastrointestinal tract and extraintestinal sites via the mesenteric lymphatic channels and thoracicduct. Feeding of an individual by total parenteral nutrition results inthe atrophy of gut-associated lymphoid tissue and a decrease inimmunoglobulin A levels. Addition of glutamine to a total parenteralnutrition solution was shown by Li et al to normalize gut-associatedlymphoid tissue population.

Work by Gismondo et al (Gismondo, M. R., Drago, L., Fassina, M. C.,Vaghi, I., Abbiati, R. and Grossi, E. (1998). Immunostimulating effectof oral glutamine. Dig. Dis. Sci, 43, 1752-1754) has indicated that theoral administration of glutamine to congenitally immunosuppressed miceprovides a positive effect on serum levels of interleukin 2 and theintestinal population of T cells.

In addition, studies in man by Fujita and Sakura (Fujita, T. andSakurai, K. (1995) Efficacy of glutamine-enriched enteral nutrition inan experimental model of mucosal ulcerative colitis. Br. J. Surg, 82,749-751) have indicated that the administration of glutamine istherapeutically beneficial to patients with inflammatory bowel disease.

It is a desire in the area of pet food products and companion animalhealth as well as farm animal health to provide diets suitable tosupport the health of non-human animals. In particular it is desire toprovide diets suitable to promote or maintain the health of alreadyhealthy non-human animals.

BRIEF SUMMARY OF THE INVENTION

The first aspect of this invention relates to a method of promotingimmunoglobulin secretions in the mucosal membranes of a non-human animalcomprising administering a foodstuff comprising glutamine to a non-humananimal.

Mucosal membranes are the moist membranes lining many tubular structuresand cavities. These membranes provide a protective layer between theexternal environment and the internal organs of an animal. Mucosalcells/tissues include mucosal coverings of the gut, the mouth, the nasalpassage, the esophagus, the stomach, the lung, the small intestine, thelarge intestine, epithelial tissue, urogenital tract, the eyes, andmammary glands.

The method of the first aspect seeks to improve and maintain the healthof a non-human animal. In particular, the animals of the first aspect ofthe invention are pet or companion animals such as cats or dogs or farmanimals such as swine (porcine), sheep (ovine) or cattle (bovine) orpoultry. The animals may be at any life-stage, such as young, adult orsenior. Accordingly, kittens, puppies, piglets, lambs, calves and chicksare covered by the present invention. The maintenance and improvement ofthe health of a pet or companion animal and of other animals, such asfarm animals is a constantly ongoing aim in the art.

It is possible to monitor the improved health of an animal as achievedby the invention in a number of ways. Two of these are feces quality andgastrointestinal (GI) tract health. By improving the health of theanimal, the invention seeks to promote and maintain good quality fecesin animals (such as pet animals). Good feces quality is of two-foldimportance. Firstly, it is a good indicator of a healthy animal (such asa pet). It is known that good feces quality usually reflects healthycolonic structure and function. Secondly, it is a much-favoredpracticality for pet-owners. The invention also aims to improve the GItract health of animals (such as pet animals). The ability to maintainand improve GI tract health can be beneficial to animal owners (such aspet owners) because it has an impact on their animal's overall health.

Without being bound by scientific theory, it is believed that byincreasing the level of secretary immunoglobulin A in the mucosalmembranes, glutamine maintains and promotes health of a non-humananimal. It is postulated that elevated levels of immunoglobulin Aimprove the defense mechanisms of the mucosal membranes by eliminatingviruses from epithelial cells and by forming a barrier which preventsthe adherence of pathogenic bacteria. For example, elevated levels ofimmunoglobulin A in the lungs and/or the nasopharynx may protect ananimal from micro-organisms that cause influenza or pneumonia. Withinthe gastrointestinal tract, immunoglobulin A is believed to decreaseintestinal permeability and to enhance intestinal absorption. Therefore,a preferred feature of the first aspect of the invention relates to amethod for increasing levels of secretory immunoglobulin A in thegastrointestinal tract comprising administering a foodstuff comprisingglutamine to the non-human animal. A further preferred feature of thefirst aspect of the invention relates to a method for increasing thelevels of secretory immunoglobulin A in the urogenital tract comprisingadministering a foodstuff comprising glutamine to a non-human animal.

It is a preferred feature of the invention that the foodstuff of thefirst aspect is administered to a non-human animal, which is healthy. Itis postulated that administering a foodstuff comprising glutamine to ahealthy non-human animal will allow the healthy status of that animal tobe maintained, as the animal will be less susceptible to viral orbacterial infection.

For the purposes of this invention, ‘health’ is defined as an absence ofclinical disease. Thus a healthy animal is an animal which does notexhibit the symptoms of a clinical disease, for example, by its immunestatus or histology. In a preferred aspect of this invention, the termhealthy encompasses animals at optimal health. In another preferredaspect of this invention, the term healthy encompasses animals atoptimal or sub optimal health, for example animals with one or moresubclinical diseases.

An assessment of the health of a particular animal can be carried out bythe owner (i.e. by assessing the quality of the feces of the animaland/or monitoring the appetite of the animal) or by an individualqualified to do so (e.g. a veterinary surgeon, dietician) by assessingthe histology and/or immune status of the animal.

The method of the first aspect comprises administering a foodstuffcomprising glutamine. The foodstuff may comprise one or more componentswhich provide a source of glutamine such as one or more of gliadin, oatbran, soya bean meal, linseed, cereals, forages, sunflower, lupin,beans, lentils, milk powder, caesin, whey or soy. For the purposes ofthis invention, cereals include barley, oats, wheat, bran and rye andforages include grass, hay, rye grass etc.

Alternatively, the foodstuff may be supplemented by a source ofglutamine. The glutamine source may be the free amino acid (preferablyL-glutamine), a peptide rich in L-glutamine or an extract containingL-glutamine. Suitable peptides rich in L-glutamine include dipeptides,tripeptides, tetrapeptides, pentapeptides, hexapeptides, longer chainpeptides or peptide mixtures. Such peptide mixtures include proteinsrich in L-glutamine, hydrolates or fractions thereof (e.g. peptidemixture(s) obtained from one or more of gliadin, oat bran, soya beanmeal, linseed, cereals, forages, sunflower, lupin, beans, lentils, milkpowder, caesin, whey or soy). Glutamine can be further provided by anextract containing L-glutamine either as a free amino acid or as apeptide containing L-glutamine (e.g. extracts of gliadin, oat bran, soyabean meal, linseed, cereals, forages, sunflower, lupin, beans, lentils,milk powder, caesin, whey or soy). Other L-glutamine derivatives includeL-glutamine salts, N-acyl derivatives of L-glutamine includingN-alkanoyl L-glutamine compounds such as N-acetyl L-glutamine. TheN-acylation of L-glutamine stabilises the peptide, in comparison withfree amino acid L-glutamine. Such peptides may be pH and fluid stable.The dipeptide can be but is not limited to L-alanyl-L-glutamine orL-glycyl-L-glutamine. The dipeptide containing L-glutamine should bestable in solution.

Preferably, the glutamine is provided as the free amino acid L-glutamineor a dipeptide containing L-glutamine. Alternatively, the glutamine isprovided either as an extract or peptide mixture from or by wheat glutenor a casein hydrosylate such as sodium caseinate.

Glutamine is preferably provided to the foodstuff at a level of from0.01% to 10% w/w on a dry matter basis. Preferably the glutamine isprovided as free glutamine or a source thereof having an equivalentamount of bioavailable glutamine. Preferably, the glutamine is providedat a level of 0.01% to 5% w/w on a dry matter basis, most preferably,approximately 1% w/w on a dry matter basis or above.

The glutamine of the invention would be provided by the foodstuff atlevels of approximately 0.01 g to approximately 1 g per kg body weightper day, more preferably, approximately 0.1 g per kg body weight orabove per day. The foodstuff is preferably administered daily, morepreferably twice daily. Where the foodstuff is a treat or snack, thefoodstuff can be administered one or more times a day, preferably fiveor more times a day. The amount of glutamine in a foodstuff maytherefore vary depending on the number of times a day the foodstuff isto be administered.

The foodstuff of the invention may be a dry product (with approximately3, 4 or 5 to approximately 15% moisture), a semi-moist product (withapproximately 15 to approximately 70% moisture) or a wet product (withapproximately 70 to approximately 90% moisture).

The foodstuff according to the present invention encompasses any productthat an animal, (such as a pet) consumes in its diet. Thus, theinvention covers standard food products as well as food snacks, such aspet food snacks (for example, snack bars, treats, biscuits and sweetproducts). The foodstuffs preferably a cooked product. It mayincorporate meat or animal derived material (such as beef, chicken,turkey, lamb, fish, blood plasma, marrow bone etc or one or morethereof). The product alternatively may be meat free (preferablyincluding a meat substitute such as soya, maize gluten or a soyaproduct) in order to provide a protein source. The product may containadditional protein sources such as soya protein concentrate, milkproteins, gluten etc.

The product may also contain a starch source such as one or more grains(e.g. wheat, corn, rice, oats, barley etc), or may be starch free.

The foodstuff of the invention is preferably produced as a dry productcontaining from approximately 3%, 4% or 5% to approximately 15%moisture. The preferred dry food is more preferably presented as smallbiscuit-like kibbles.

The foodstuff is preferably packaged. In this way, the consumer is ableto identify, from the packaging, the ingredients in the foodstuff andconfirm that it is suitable for the particular animal (such as a pet) inquestion. The packaging may be metal (usually in the form of a tin orflexifoil), plastic (usually in the form of a pouch), paper or card. Theamount of moisture in any product may influence the type of packaging,which can be used or is required.

The foodstuff of the first aspect can be provided as a food supplement.The food supplement can be a powder, sauce, topping, biscuit, kibble,pocket or tablet that can be administered with or without an additionalfoodstuff. Where the food supplement is administered with an additionalfoodstuff, the food supplement can be administered sequentiallysimultaneously or separately. The food supplement may mixed with thefoodstuff, sprinkled over the foodstuff or served separately.Alternatively, the food supplement can be added to a liquid provided fordrinking such as water or milk.

The foodstuff can be made according to any method known in the art.Foodstuffs for pet animals can be any, including such as in Waltham Bookof Dog and Cat Nutrition, Ed. ATB Edney, Chapter by A. Rainbird,entitled “A Balanced Diet” in pages 57 to 74 Pergamon Press Oxford.

The glutamine may be mixed with the other components of the foodstuff orcan be added to the completed foodstuff. In a preferred feature of theinvention, the glutamine is coated or sprayed on to the surface of thefoodstuff. Alternatively, one or more components comprising glutamineare admixed, with one or more other components of the foodstuff.

The second aspect of the invention relates to the use of glutamine inthe manufacture of a foodstuff for preventing or treating infection inthe gastrointestinal tract.

It is proposed that the administration of the foodstuff will result inan increase in the level of secretary immunoglobulin A in thegastrointestinal tract. It is postulated that such elevated levels ofimmunoglobulin A will prevent viral or bacterial infection byeliminating viruses from epithelial cells and forming a barrier whichprevents adherence of pathogenic bacteria. In addition, elevatedimmunoglobulin A levels are believed to decrease intestinal permeabilityand enhance intestinal absorption. Thus the second aspect of theinvention further relates to the use of glutamine in the manufacture ofa foodstuff for preventing or treating bacterial or viral infectionssuch as calicivirus in the gastrointestinal tract.

All preferred features of the first aspect of the invention also relateto the second aspect.

The third aspect of the invention relates to the use of glutamine in themanufacture of a foodstuff for the promotion or maintenance of theurogenital health of a non-human animal. In particular, the third aspectrelates to the use of glutamine in the manufacture of a foodstuff forpreventing or treating infection in the urogenital tract of a non-humananimal. For the purposes of the third aspect, the infections arepreferably bacterial or viral infections of the urogenital tract, suchas calicivirus.

All preferred features of the first and second aspects of the inventionalso relate to the third aspect.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be illustrated with reference to the followingnon-limiting examples.

EXAMPLES

Composition of a Foodstuff Comprising Glutamine.

The foodstuff is a dry product containing less than 10% water. Thefoodstuff comprises the following ingredients (˜is approximately). Rice˜20% Poultry ˜23% Maize ˜17% Maize meal  ˜9% Beef Tallow ˜10% Glutamine ˜1%

All ingredients except glutamine are mixed, cooked and formed into a drykibble. Glutamine (provided as L-glutamine) is then sprayed onto theexternal surface of the foodstuff.

Experimental Data Example 1

The study was carried out using eight members of the cat colonic healthpanel, which were known to be in good (intestinal) health. Cats werewormed and vaccinated 6 months prior to the start of the trial.

The cats underwent the following trial regime; 14 days Control diet 28days Glutamine enriched diet 14 days Control diet

Both the control diet and the glutamine enriched diet provided 405kCal/100 g. The control diet was a dry diet containing approximately 4%water. The control diet comprised the following ingredients (˜isapproximately): Poultry ˜37% Beef Tallow ˜10% Rice ˜20% Maize meal andgluten ˜26% Sunflower oil  ˜3% Brewers yeast and vitamins  ˜3%

The glutamine-supplemented diet comprised 1% dry weight by weightglutamine provided as L-glutamine. The glutamine was sprayed onto theexternal surface of the dry control product.

Measurement of Immunoglobulin Production

Levels of immunoglobulin A production by mid colon biopsy samples weremeasured by enzyme linked immunosorbent assay (ELISA). IgA ELISA testwas obtained from Bethyl and performed as described in provided protocolsheets. In short, 96 well microplates were taken and coated with 100 μlanti-canine IgA overnight at 4° C. After each step the plates werewashed with ELISA wash (50 Mm) Tris, pH 8.0, 0.1M NaCl, 0.05% Tween 20).Unreacted sites were blocked with tris-buffered saline (TBS) containing1% bovine serum albumin (BSA) for 30 minutes. Standards and samples werediluted as required, 100 μl added to the plate and incubated for 1 hourat room temperature. After washing, horseradish peroxidase-conjugatedanti-canine IgA immunoglobulins were diluted as described in theprotocol and incubated on the plate for 1 hour at room temperature. 200μl of 3,3′,5,5′-tetramethyl benzidine (TMB) was added to the plate as anenzyme substrate and the reaction was stopped with 100 μl of 0.5M H₂SO₄after 30 minutes. Finally, the absorbence was readspectrophotometrically at 450 nm using an ELISA plate reader.

Results

A significant increase in IgA production by the colon was found in thesamples taken from below the transwell when cats were fed dietscontaining 1% glutamine (P=0.048, GLM) compared to the other threediets. Results are summarized below in the below table. TABLE IgAproduction by biopsy samples IgA production (ng/mg protein) DietIntestinal Sample Standard  569.8 ± 206.7 (a) Glutamine 1003.1 ± 762.9(b)Same letter denotes no significant different (p > 0.05).

1. A method of promoting immunoglobulin A secretion in a mucosalmembrane of a non-human animal comprising administering a foodstuffcomprising glutamine to the non-human animal.
 2. The method of claim 1,wherein the mucosal membrane is the gastrointestinal tract of thenon-human animal.
 3. The method of claim 1, wherein in the mucosalmembrane is the urogenital tract of the non-human animal.
 4. A method asclaimed in claim 1 for the use of maintaining or improving the health ofa non-human animal.
 5. The method of claim 4, wherein the non-humananimal is healthy.
 6. The method of claim 1, wherein the non-humananimal is a companion animal selected from the group consisting of a catand a dog, or wherein the animal is a porcine, ovine, bovine or poultryanimal.
 7. The method of claim 1, wherein glutamine is one or more ofL-glutamine, a peptide comprising glutamine or an extract comprisingglutamine.
 8. The method of claim 7, wherein the peptide is one or moreof a dipeptide, tripeptide, tetrapeptide, pentapeptide, hexapeptide, alonger chain peptide or a peptide mixture.
 9. The method of claim 8,wherein the peptide mixture is derived from one or more of gliadin, oatbran, soya bean meal, linseed, cereals, forages, sunflower, lupin,beans, lentils, milk powder, caesin, whey, soy casein hydrosylate orwheat gluten.
 10. The method of claim 1, wherein glutamine is providedto the foodstuff at a level of approximately 1% w/w on a dry matterbasis or above.
 11. The method of claim 1, wherein the foodstuffcontains from approximately 3% to approximately 15% moisture.
 12. Themethod as of claim 1, wherein glutamine is provided to the non-humananimal at a level of approximately 0.1 g per kilogram body weight orabove per day.
 13. The method as of claim 1, wherein the foodstuff isprovided one or more times per day.
 14. A method of producing acomposition for preventing or treating infection in the gastrointestinaltract of a non-human animal comprising the step of providing glutamineto a foodstuff.
 15. A method of producing a composition for promotingurogenital health in a non-human animal comprising the step of providingglutamine to a foodstuff.
 16. The method of claim 15, wherein thecomposition prevents or treats infection in the urogenital tract of anon-human animal.
 17. The method claim 14, wherein the infection iscaused by a virus or a bacteria.
 18. The method of claim 14, wherein thenon-human animal is healthy.
 19. The method of claim 14, wherein thenon-human animal is a companion animal selected from the groupconsisting of a cat and a dog or wherein the animal is a porcine, ovine,bovine or poultry animal.
 20. The method of claim 19, wherein glutamineis one or more of L-glutamine, a peptide comprising glutamine or anextract comprising glutamine.
 21. The method of claim 20, wherein thepeptide is one or more of a dipeptide, tripeptide, tetrapeptide,pentapeptide, hexapeptide, a longer chain peptide or a peptide mixture.22. The method of claim 21, wherein the peptide mixture is derived fromone or more of gliadin, oat bran, soya bean meal, linseed, cereals,forages, sunflower, lupin, beans, lentils, milk powder, caesin, whey,soy, casein hydrosylate or wheat gluten.
 23. The method of claim 14,wherein the glutamine is provided to the composition at a level ofapproximately 1% w/w on a dry matter basis or above.
 24. The method ofclaim 14, wherein the composition contains from approximately 3%, 4% or5% to approximately 15% moisture.
 25. The method of claim 14, whereinthe glutamine is provided to the non-human animal at a level ofapproximately 0.1 g per kilogram body weight or above per day.
 26. Themethod of claim 14, wherein the composition is provided one or moretimes per day.
 27. (canceled)